In the typical large horizontal glass furnace for continuous manufacture, the glass undergoes the stages of being prepared by melting batch materials, which float on the molten glass at one end of the furnace, fining the molten glass in a succeeding zone, which in certain cases may be isolated from the first zone by a wall, and conditioning, quieting and cooling the molten glass to a temperature suitable for manufacture into glass products in a conditioning or working zone, which may also be substantially isolated. These furnaces may be gas fired or electric melt furnaces.
A common system for producing glass filaments or fibers includes a furnace having forehearths extending therefrom through which molten glass in the furnace is carried to a plurality of spaced apart bushings or other devices, such as spinners, located along the bottom wall of the forehearths. The forehearths can extend directly from the furnace or can extend as branches from one or more main channels carrying the molten glass from the furnace. The glass from each forehearth flows through openings by gravity into the bushings therebelow with molten glass streams from the bushings or spinners being formed into glass filaments or fibers.
Vertical melters are known which permit glass to be formed directly from a furnace or melting region. To accomplish this, one type of arrangement uses a strip or screen of platinum or platinum alloy disposed in the furnace region. The platinum typically is perforated or slotted to facilitate circulation of molten glass. Electric current is passed through the strip or screen to melt the raw batch by resistive heating of the screen. A forming means, such as a bushing, is connected directly to the melter to provide streams of molten glass that are formed into fibers by various means.